Who you deal with
Four bodies, and which one you meet depends on the water. The waterways and shipping directorate handles all inland examinations. The maritime employers' liability body handles everything seagoing.
At twelve passengers
Germany has a national vessel category, the Fahrgastboot, that sits below a full passenger ship and is built directly on top of recreational design categories. On zone 3 waterways it requires at least CE design category C, which this boat already holds. The category is the qualifying criterion itself rather than supporting evidence. An examination commission then checks the boat against a defined list.
At twenty passengers
The same category carries up to thirty-five passengers on the waterways listed in Annex IX, which is essentially the whole Berlin and Brandenburg network, the German Mosel including Trier, the upper Elbe from the Czech border to Kreinitz including Dresden, the Saale, the Müritz and the Mecklenburg lakes. The additional work is a defibrillator and a capacity and stability recalculation. This is the strongest position anywhere in Europe above twelve passengers.
Who may drive it
The manning rules require a skipper plus a deckhand, with a single-handed derogation in zones 3 and 4. Above twelve passengers you also need a Union certificate of competence for passenger navigation.
Hiring it out without a crew
This is the lightest route in Germany and it is already open. The EU Declaration of Conformity is named in the hire regulation as statutory proof of fitness for commercial hire, valid ten years. The 2018 declaration already qualifies, and it runs until 2028.
Where the engine matters
The Bodensee is closed to this boat: every newly registered engine needs a specific exhaust approval and the recognised list stops at 59 kW. Elsewhere in Germany we found no restriction. Note also that Fahrgastboote are not permitted on the Rhine at all, and that the seagoing commercial certificate expressly does not cover harbour tours or water-taxi work.